Like previous censuses, the 1940 U.S. census is divided by state, by county, and then by enumeration district (ED). Whenever we source a census record, it's important to include the publication number, the microfilm number, and the ED number. Since the 1940 census was released on April 2, 2012, without an everyname index, those ED numbers become critically important while waiting for various volunteer groups to finish indexing the census.
If you have the 1940 street address but need the ED number, check Steve Morse's Unified 1940 Census ED Finder. Type in the address, select "ED description," and then "More Details" for ED number.
If you have your ED number, you can focus your research on a specific location. Besides the National Archives and Record Administration's official 1940 census site, other web sites such as MyHeritage.com, FamilySearch, and Ancestry are hosting the 3.8 million images.
For the 1940 census, the publication number is T627. Below, you will find a chart that includes the microfilm number, county (city), and ED numbers.
1940 U.S. Census (T627) for Massachusetts
Roll #: County (City): ED Numbers
1565: Barnstable: 1-1 to 1-33
1566: Barnstable: 1-34 to 1-59
1567: Berkshire: 2-1 to 2-16, 2-18 to 2-36
1568: Berkshire: 2-37 to 2-73
1569: Berkshire: 2-74 to 2-107
1570: Berkshire: 2-108 to 2-133, 2-135 to 2-145, 2-17, 2-134
1571: Bristol: 3-1 to 3-27
1572: Bristol: 3-28 to 3-63
1573: Bristol: 3-64 to 3-93
1574: Bristol: 3-94 to 3-120
1575: Bristol: 3-121 to 3-147
1576: Dukes: 4-1 to 4-20
1577: Essex: 5-1 to 5-31
1578: Essex: 5-32 to 5-56
1579: Essex: 5-57 to 5-99
1580: Essex: 5-100 to 5-132
1581: Essex: 5-133 to 5-151
1582: Essex; Essex (Lawrence): 5-152 to 5-157; 5-158 to 5-181
1583: Essex (Lawrence): 5-182 to 5-212
1584: Essex (Lawrence): 5-213 to 5-227
1585: Essex: 5-228 to 5-243
1586: Essex: 5-244 to 5-273
1587: Essex: 5-274 to 5-298
1588: Essex: 5-299 to 5-326
1589: Essex: 5-327 to 5-370
1590: Essex: 5-371 to 5-405
1591: Franklin: 6-1 to 6-3, 6-15, 6-48, 6-4 to 6-29
1592: Franklin: 6-30 to 6-65
1593: Hampden: 7-1 to 7-36
1594: Hampden: 7-37 to 7-66
1595: Hampden (Holyoke): 7-67 to 7-101
1596: Hampden (Holyoke); Hampden: 7-102 to 7-125; 7-126 to 7-139
1597: Hampden: 7-140 to 7-160
1598: Hampden: 7-161 to 7-204
1599: Hampshire: 8-1 to 8-41
1600: Hampshire: 8-42 to 8-81
1601: Middlesex: 9-1 to 9-31
1602: Middlesex: 9-32 to 9-46, 9-482, 9-47 to 9-54, 9-205, 9-536, 9-55 to 9-63
1603: Middlesex: 9-64 to 9-109
1604: Middlesex (Everette): 9-110 to 9-135
1605: Middlesex (Everette): 9-136 to 9-154
1606: Middlesex: 9-155 to 9-178
1607: Middlesex: 9-179 to 9-203, 9-537, 9-204, 9-206 to 9-210
1608: Middlesex (Malden): 9-211 to 9-239
1609: Middlesex (Malden): 9-240 to 9-271
1610: Middlesex: 9-272 to 9-295
1611: Middlesex (Medford): 9-296 to 9-318
1612: Middlesex (Medford): 9-319 to 9-354
1613: Middlesex: 9-355 to 9-392
1614: Middlesex (Newton): 9-393 to 9-419
1615: Middlesex (Newton): 9-420 to 9-444
1616: Middlesex (Newton); Middlesex: 9-445 to 9-463; 9-464 to 9-469
1617: Middlesex: 9-470 to 9-481, 9-483 to 9-497
1618: Middlesex: 9-498 to 9-524
1619: Middlesex (Waltham): 9-525 to 9-535, 9-538 to 9-570
1620: Middlesex (Watertown): 9-571 to 9-599
1621: Middlesex (Watertown); Middlesex: 9-600 to 9-607; 9-608 to 9-627
1622: Middlesex: 9-628 to 9-658
1623: Nantucket: 10-1 to 10-13
1624: Norfolk: 11-1 to 11-28
1625: Norfolk (Brookline): 11-29 to 11-57
1626: Norfolk (Brookline); Norfolk: 11-58 to 11-73; 11-74 to 11-91
1627: Norfolk: 11-92 to 11-101, 11-118, 11-102 to 11-117, 11-119
1628: Norfolk: 11-120 to 11-151
1629: Norfolk: 11-152 to 11-171
1630: Norfolk (Quincy): 11-172 to 11-198
1631: Norfolk (Quincy): 11-199 to 11-232
1632: Norfolk (Quincy); Norfolk: 11-233 to 11-246; 11-247 to 11-258
1633: Norfolk: 11-259 to 11-289
1634: Norfolk: 11-290 to 11-313
1635: Plymouth; Plymouth (Brockton): 12-1 to 12-15; 12-16 to 12-32
1636: Plymouth (Brockton): 12-33 to 12-58
1637: Plymouth (Brockton); Plymouth: 12-59 to 12-78; 12-79 to 12-86
1638: Plymouth: 12-87 to 12-93, 12-96, 12-94, 12-95, 12-97 to 12-109, 12-111, 12-128, 12-110, 12-112 to 12-117
1639: Plymouth: 12-118 to 12-127, 12-129 to 12-156
1640: Plymouth: 12-157 to 12-185
1641: Suffolk (Chelsea): 13-1 to 13-33
1642: Suffolk (Chelsea): 13-34 to 13-51
1643: Suffolk (Revere): 13-52 to 13-74
1644: Suffolk: 13-75 to 13-107
1645: Worcester: 14-1 to 14-12, 14-326, 14-13 to 14-30, 14-152, 14-31, 14-32
1646: Worcester: 14-33 to 14-58
1647: Worcester (Fitchburg): 14-59 to 14-88
1648: Worcester (Fitchburg): 14-89 to 14-107
1649: Worcester (Gardner): 14-108, 14-109, 14-317, 14-110 to 14-130
1650: Worcester: 14-131, 14-132, 14-245, 14-309, 14-133 to 14-141, 14-151, 14-142 to 14-149
1651: Worcester: 14-150, 14-153 to 14-181
1652: Worcester: 14-182 to 14-208
1653: Worcester: 14-209 to 14-244, 14-246, 14-247
1654: Worcester: 14-248 to 14-268
1655: Worcester: 14-269 to 14-278, 14-324, 14-279 to 14-304
1656: Worcester: 14-305 to 14-308, 14-310 to 14-316, 14-318 to 14-323, 14-325
1657: Suffolk (Boston): 15-1 to 15-27
1658: Suffolk (Boston): 15-28 to 15-59
1659: Suffolk (Boston): 15-60 to 15-91
1660: Suffolk (Boston): 15-92 to 15-126
1661: Suffolk (Boston): 15-127 to 15-157
1662: Suffolk (Boston): 15-158 to 15-189
1663: Suffolk (Boston): 15-190 to 15-222
1664: Suffolk (Boston): 15-223 to 15-255
1665: Suffolk (Boston): 15-256 to 15-287, 15-769 to 15-771
1666: Suffolk (Boston): 15-288 to 15-327
1667: Suffolk (Boston): 15-328 to 15-358
1668: Suffolk (Boston): 15-359 to 15-391
1669: Suffolk (Boston): 15-392 to 15-420
1670: Suffolk (Boston): 15-421 to 15-451
1671: Suffolk (Boston): 15-452 to 15-479
1672: Suffolk (Boston): 15-480 to 15-502
1673: Suffolk (Boston): 15-503 to 15-527
1674: Suffolk (Boston): 15-528 to 15-553
1675: Suffolk (Boston): 15-554 to 15-581
1676: Suffolk (Boston): 15-582 to 15-611
1677: Suffolk (Boston): 15-612 to 15-632
1678: Suffolk (Boston): 15-633 to 15-655
1679: Suffolk (Boston): 15-656 to 15-683
1680: Suffolk (Boston): 15-684 to 15-712
1681: Suffolk (Boston): 15-713 to 15-739
1682: Suffolk (Boston): 15-740 to 15-768
1683: Middlesex (Cambridge): 16-1 to 16-39
1684: Middlesex (Cambridge): 16-40 to 16-75
1685: Middlesex (Cambridge): 16-76 to 16-108
1686: Middlesex (Cambridge): 16-109 to 16-136
1687: Bristol (Fall River): 17-1 to 17-30
1688: Bristol (Fall River): 17-31 to 17-76
1689: Bristol (Fall River): 17-77 to 17-104
1690: Bristol (Fall River): 17-105 to 17-142
1691: Middlesex (Lowell): 18-1 to 18-39
1692: Middlesex (Lowell): 18-40 to 18-80
1693: Middlesex (Lowell): 18-81 to 18-106
1694: Middlesex (Lowell): 18-107 to 18-136
1695: Essex (Lynn): 19-1 to 19-37
1696: Essex (Lynn): 19-38 to 19-80
1697: Essex (Lynn): 19-81 to 19-111
1698: Bristol (New Bedford): 20-1 to 20-36
1699: Bristol (New Bedford): 20-37 to 20-67
1700: Bristol (New Bedford): 20-68 to 20-98
1701: Bristol (New Bedford): 20-99 to 20-132
1702: Middlesex (Somerville): 21-1 to 21-35
1703: Middlesex (Somerville): 21-36 to 21-64
1704: Middlesex (Somerville): 21-65 to 21-80
1705: Middlesex (Somerville): 21-81 to 21-107
1706: Hampden (Springfield): 22-1 to 22-20
1707: Hampden (Springfield): 22-21 to 22-48
1708: Hampden (Springfield): 22-49 to 22-83
1709: Hampden (Springfield): 22-84 to 22-120
1710: Hampden (Springfield): 22-121 to 22-137
1711: Hampden (Springfield): 22-138 to 22-165
1712: Worcester (Worcester): 23-1 to 23-19
1713: Worcester (Worcester): 23-20 to 23-42
1714: Worcester (Worcester): 23-43 to 23-78
1715: Worcester (Worcester): 23-79 to 23-106
1716: Worcester (Worcester): 23-107 to 23-133
1717: Worcester (Worcester): 23-134 to 23-154
1718: Worcester (Worcester): 23-155 to 23-185
1719: Worcester (Worcester): 23-186 to 23-220
If you would like to help index the 1940 U.S. census, check out my article on how you can help. The more indexers, the quicker we'll have an everyname index ready to go!