                     [NOT FOR PUBLICATION]

                UNITED STATES COURT OF APPEALS
                     FOR THE FIRST CIRCUIT

                                         

No. 97-2088

                      MARIA M. SANTIAGO,

                     Plaintiff, Appellant,

                              v.

               COMMISSIONER OF SOCIAL SECURITY,

                     Defendant, Appellee.

                                         

         APPEAL FROM THE UNITED STATES DISTRICT COURT

                FOR THE DISTRICT OF PUERTO RICO

      [Hon. Carmen Consuelo Cerezo, U.S. District Judge]

                                         

                            Before

                     Selya, Circuit Judge,
                  Cyr, Senior Circuit Judge,
                  and Boudin, Circuit Judge.

                                         

Melba N. Rivera-Camacho and Melba N. Rivera Camacho &amp; Assocs. on
brief for appellant.
Guillermo Gil, United States Attorney, Lillian Mendoza-Torro,
Assistant U.S. Attorney, and Wayne G. Lewis, Assistant Regional Counsel,
Social Security Administration, on brief for appellee.

                                         
                       March 18, 1998

                                         
  Per Curiam.  Claimant Maria Santiago appeals a district
court judgment that affirmed a decision by the Commissioner of
Social Security denying claimant's application for disability
benefits.  We have thoroughly reviewed the record and the
parties' briefs on appeal.  We conclude that the Commissioner's
decision is supported by substantial evidence and uninfected by
legal error.  We add the following comments.
    1.  Claimant asserts, without citation to the record or
case law, that she proved that she is unable to perform her
past relevant work as a housekeeper.  We disagree.  The record
discloses that this work required claimant to perform only
simple, routine tasks for up to 4-5 hours, and that both of the
Commissioner's consulting psychologists found claimant's
ability to perform such tasks was not significantly limited. 
Although claimant was represented by counsel at her
administrative hearing, she never explained how her impairments
prevented her from performing her past work.  Thus, she failed
to meet her burden at step four.  See, e.g., Santiago v.
Secretary of Health and Human Services, 944 F.2d 1, 5 (1st Cir.
1991)(per curiam); Gray v. Heckler, 790 F.2d 369, 372, 375 (1st
Cir. 1985)(per curiam);  Gonzalez Perez v. Secretary of Health
and Human Services, 572 F2d 886, 888 (1st Cir. 1978).        
    2.  Claimant next says that the administrative law judge
(ALJ) should have evaluated her mental impairment under the
listing for Somatoform Disorders (12.07), not under the
listing for Affective Disorders (12.04).  She maintains that
the ALJ applied the wrong listing and, in so doing, 
impermissibly substituted his own lay opinion on the nature of
claimant's mental impairment for the opinion of his medical
advisor, Dr. Perez Arzola.  Claimant errs on both counts.   Dr.
Perez Arzola's testimony in no way established the presence of
a somatoform disorder, and there was ample evidence to support
the ALJ's use of the listing governing affective disorders. 
    3.  Vocational expert testimony was not required where
claimant failed to meet her burden at step four and the
Commissioner procured expert assessments of claimant's residual
functional capacity.  
    Claimant's remaining contentions on appeal are meritless. 
  Affirmed.
