Tackett

In 1993, Richard Tackett applied for Social Security disability insurance benefits under 42 U.S.C. §§ 423 (d) and 416(i) of the Social Security Act. In his application, he alleged that he has been disabled since September 16, 1991. In March of 1995, the Administrative Law Judge (“ALJ”) determined that under the Guidelines 2 Tackett’s severe knee problems qualified him as disabled since his fiftieth birthday on February 7th, 1995, but that Tackett was not qualified as disabled from September 16, 1991 until February 6, 1995, the day before his fiftieth birthday.

*1097 Tackett appeals the ALJ’s decision to deny him benefits for the period from September 16, 1991 to February 6, 1995. He claims that the ALJ’s decision denying him benefits during that period is not supported by substantial evidence and is based on errors of law. The district court had jurisdiction pursuant to 42 U.S.C. § 405 (g) and affirmed the denial of benefits for that period. We have jurisdiction pursuant to 28 U.S.C. § 1291 , and we reverse.

I. Facts and Prior Proceedings.

Tackett has had problems with his knees for well over ten years. One of his treating physicians stated that Tackett’s left knee was “one of…